1. Field of the Invention
The present invention relates generally to an image recording apparatus and, more particularly, to an image recording apparatus such as a reader printer for projecting an image from an image bearing medium such as a microfilm onto a screen and for recording the projected image on an image recording medium.
2. Description of the Prior Art
Referring to FIG. 4 which illustrates a diagrammatically conventional type of image recording apparatus, a rotary mirror 202 is dispose in the vicinity of a projection lens 201 for projecting an image on a microfilm 200 on an enlarged scale, and the rotary mirror 202 is rotated in a scanning manner, thereby effecting projection and recording of the image.
When an image on the microfilm 200 is to be projected onto a screen 203, the reflection plane of the rotary mirror 202 is tilted slightly upwardly as viewed in FIG. 4, and image rays from the microfilm 200 are projected onto the screen 203 by mirrors 204 and 205 disposed at locations generally above the rotary mirror 202.
Recording of an image of the microfilm 200 is effected in the following manner. The rotary mirror 202 is rotated in the direction indicated by an arrow A for scanning movement, and the image rays are projected by mirrors 206 and 207 onto a photosensitive drum 208 as it rotates in the direction indicated by an arrow B in synchronization with the rotation of the rotary mirror 202. In consequence, the image of the microfilm 200 is projected onto the photosensitive drum 208 in a slit-like form and thus a corresponding electrostatic latent image is formed on the photosensitive drum 208. Thereafter, the electrostatic latent image is recorded on an image recording medium, for example, recording paper by a known electrophotographic process.
However, such a prior art arrangement involves the following problems. As shown in FIG. 4, the optical axis of the image rays is not horizontally formed between the rotary mirror 202 and the mirror 206 nor between the mirror 206 and the mirror 207 which is located vertically above the photosensitive drum 208. During assembly of the apparatus, therefore, it is difficult to accurately position the respective mirrors 206 and 207 in predetermined locations, and an error easily occurs in the angle of inclination of each of the mirrors 206 and 207. As a result, the optical axes of the image rays may deviate, and thus it would be impossible to select a desired region of an image to be recorded. Also, a printed image of uniform density may not be obtained due to uneven illumination.
In addition, since the optical axes of the reflected rays is not horizontal, the prior art apparatus requires a vertically expanded space for accommodating the mirrors 206 and 207 and, therefore, involves the problem of an inevitable increase in the size of the apparatus.
As is known, reader printers of this type include two major sections. One section is an image forming section whose constituent elements includes a reader optical system, a printer optical system, and a photosensitive member with associated components disposed around it such as a development unit and a cleaner. The other section is a sheet feeding section for feeding sheets of recording paper. These sections include a multiplicity of members which are combined in a complicated arrangement. Therefore, even if a cover is detachably arranged at one side of the apparatus, it is difficult to smoothly perform checking and maintenance when necessary, such as removal of any sheet which becomes jammed in a sheet feeding path or cleaning of the above-described sections.
To solve these problems, it has been proposed to provide a reader printer which includes a body constituted by an upper assembly and a lower assembly, the upper and lower assemblies being pivotally joined at one side thereof by means of a hinge, with one of the assemblies accommodating image forming means such as a photosensitive member, a development unit and an electrostatic charger can be opened and closed.
However, the assembly of such prior art apparatus includes, in addition to the image forming means, further includes other components which are arranged in a densely packed space, for example, a scanning mechanism and an optical system such as a mirror for scanning image rays. It is therefore still difficult to smoothly perform checking and maintenance of the image forming section.